Roughly 90 percent of a washing machine’s energy goes to heating water, so switching to cold saves the average household around $60 a year.
Use a cold-water detergent, since modern formulas are designed to lift dirt without heat.
Reserve warm or hot water only for heavily soiled items, cloth diapers, or when someone has been sick.
Wash full loads and skip the extra rinse, because the machine works most efficiently when it is full but not stuffed.
It is one of the few savings that costs nothing and needs no new equipment at all.